Process for the beneficiation of titaniferous ores

Abstract

The invention relates to the beneficiation of both natural and artificial titaniferous ores, specifically ilmenites by adding to the ores a fluoride, preferably a normally insoluble fluoride in an amount such that the percentage of fluorine ion relative to the titania values lies between 13% and 50%, adding to the mixture hydrochloric acid, the fluorine ions acting as an activating agent. After dissolution, the titanium is precipitated out, as a mixture of titanium dioxide, titanium oxy hydroxy fluoride and titanium oxy fluoride, the iron values largely remaining in solution.

I claim: 
     
       1. A process for the beneficiation of titaniferous ores including mixing the ore with an insoluble source of fluoride ions which source becomes soluble under the following conditions of the process, the fluoride concentration relative to the titania values in the ore lying between 13% and 50% by weight and heating the mixture with dilute hydrochloric acid at a temperature not more than atmospheric boiling point to thereby dissolve a substantial part of the titanium and iron values of the ore. 
     
     
       2. A process as claimed in claim 1 wherein the concentration of fluoride lies between 20% and 40% by weight. 
     
     
       3. A process as claimed in claim 2 wherein the fluoride is calcium fluoride. 
     
     
       4. A process as claimed in claim 1 wherein the acid concentration lies between 20% and 25% (W/V). 
     
     
       5. A process as claimed in claim 4 wherein the mixture is heated to the boiling point of the acid and whilst heating is agitated. 
     
     
       6. A process as claimed in claim 1 wherein after dissolution the supernatent liquid is treated to precipitate the major part of the titanium values whilst leaving the iron and other values in solution. 
     
     
       7. A process as claimed in claim 6 wherein the volume of the liquid is reduced to such a level that spontaneous precipitation of the titanium values occurs. 
     
     
       8. A process as claimed in claim 6 wherein precipitation is effected by the addition of a seed or a seeding material to the liquid. 
     
     
       9. A process as claimed in claim 6 wherein the solution is fed to an acid recovery plant from which hydrochloric acid which has a concentration of between 20% and 25% is obtained, the acid being fed to the digester, at about the temperature at which it leaves the plant. 
     
     
       10. A process as claimed in claim 6 wherein the precipitate is a mixture including titanium oxy hydroxy fluoride and titanium oxy fluoride and titanium dioxide, and said titanium oxy hydroxy fluoride is heated to decompose into titanium dioxide and titanium oxy fluoride which on further heating decomposes to titanium dioxide and titanium tetrafluoride which can be condensed. 
     
     
       11. A process as claimed in claim 10 wherein the titanium oxy hydroxy fluoride and titanium oxy fluoride are treated with hot steam and decomposed to titanium dioxide and hydrogen fluoride. 
     
     
       12. A continuous process for the beneficiation of titaniferous ores as herein defined, including feeding ore and an insoluble fluoride to a rotary digester, the concentration of fluoride ions relating to the titania values in the ore lying between 13% and 50% by weight feeding hydrochloric acid having a concentration of between 20% and 25% (W/V) to the digester, heating the mixture and delivering from the digester, a liquid containing a large percentage of the titanium and iron values from the ore and solid materials which include unreacted ore, undissolved fluoride and inclusions from the core, treating and the liquid to precipitate the titanium values therefrom. 
     
     
       13. A process as claimed in claim 12 wherein the volume of the liquid is reduced to such a level that spontaneous precipitation of the titanium values occurs. 
     
     
       14. A process as claimed in claim 12 wherein precipitation is effected by the addition of a seed or a seeding material to the liquid. 
     
     
       15. A process as claimed in claim 12 wherein material to agitate the mixture is added to the digester. 
     
     
       16. A batch process for the beneficiation of titaniferous ores including adding to the ores, an insoluble fluoride which source becomes soluble under the following conditions of the process, at a fluoride ion concentration relating to the titania values lying between 13% and 50% by weight, adding hydrochloric acid having a concentration of between 20% and 25% by weight to a digester, heating the mixture, removing from the digester, a liquid containing a large percentage of the titanium and iron values from the ore and solid materials which include unreacted ore, fluoride and inclusions from the ore, and treating the liquid to selectively precipitate the titanium values therefrom. 
     
     
       17. A process as claimed in claim 16 wherein the value of the liquid is reduced to such a level that spontaneous precipitation of the titania values occurs. 
     
     
       18. A process as claimed in claim 16 wherein precipitation is effected by the addition of a seed or a seeding material to the liquid. 
     
     
       19. A process for the beneficiation of titaniferous ores consisting essentially of mixing the ore with an insoluble source of fluoride ions which source becomes soluble under the following conditions of the process, the concentration of said source of fluoride relative to the titania values in the ore lying between 13% and 50% by weight and heating the mixture with dilute hydrochloric acid at a temperature not more than the atmospheric boiling point to thereby dissolve a substantial part of the titanium and iron values of the ore.